The invention relates to a holding apparatus for electronic money in an electronic money processing system. In the present application, the processing system for the electronic money is referred to as an "electronic money system" for simplicity of explanation.
In recent years, an electronic money system for transmitting and receiving electronic money by a communication between cards in each of which the electronic money is contained has been proposed. The card which is used for such a system is constructed by, for example, a microprocessor having therein a communicating function and a memory such as an EEPROM or the like to store a processing program and a balance of the electronic money. The electronic money of the card can be deposited and drawn into/from other cards by using an exclusive-use terminal or through an electronic money system which is constructed in a manner such that a terminal equipped in a bank, a shop, an individual home, or the like can arbitrarily be connected through a communication line.
The electronic money system proposed above is under development because which function and form each equipment constructing the system should have is not determined yet.
In the following embodiment of the present invention, a storing circuit to hold information of a money amount of electronic money and a money amount information writing circuit to write the money amount information into the storing circuit are constructed as one pair. The storing circuit of the pair can be accessed and rewritten by the money amount information writing circuit, and the information in the storing circuit cannot be rewritten without intervention of the money amount information writing circuit, thereby maintaining the safety of the electronic money. In the electronic money system proposed above, an IC card is proposed as a holding apparatus for holding the electronic money. In the following embodiment of the invention, however, the IC card is not an absolute necessary condition.